What is the proper name for idiomatic, exclamative phrases? [duplicate]

I'm wondering what the proper term would be for exclamations like "Hell's bells!", "Billions of blue blistering barnacles!", and "By Lucifer's Beard!". Specifically, I'm wondering about phrases, uttered either in amazement or under some kind of stress, and that are idiomatic (in the sense that the words themselves do not convey the meaning without context). Is there an actual English term for such utterances?

I'd prefer a single term to describe them, but a phrase would do. I would like something a little less of a mouthful than "idiomatic exclamation", and hopefully in wider usage.

I would call them expletives (see https://www.collinsdictionary.com/dictionary/english/expletive ), though expletives are usually thought of as being 'swear words' and two of your examples are rather unusual!

Interjection

Interjections, like "wow" and "ouch", are solely designed to convey emotion in an abrupt and exclamatory way. They express meaning or feeling in a word or two. They do not relate grammatically to the other parts of the sentence, nor do they help the reader understand the relationship between words and phrases in the sentence.

Instead, interjections simply convey the way the author (or speaker) is feeling. Interjections are rarely used in academic or formal writing; they're more common in fiction or artistic writing. They're usually, but not always, offset by an exclamation mark (which is also used to show emotion).